It is generally known to provide a continuous conveyor belt extending over and under the floor of a trailer for moving trailer contents, such as rock, sand, vegetables, grain, and the like, toward the front or rear of the trailer, respectively, when loading or unloading the trailer. Similarly, it is known to provide cables over the floor of a trailer that may be pulled by winches to move trailer contents, such as boxes, pallets, and the like, toward the front or rear of the trailer, respectively, when loading or unloading the trailer.